1. Field of the Invention
The present invention relates to an active thermal insulation and its ability to conserve energy by improving the thermal resistance, R, of an insulated structure beyond known values published to date.
2. Description of the Prior Art
Building structures built for human occupancy contain heating and cooling equipment to maintain a desired level of comfort. Insulation is placed in the walls, floors and ceilings of the building envelope. Insulation material relies upon trapped air within or about the material. It is a passive material with a fixed thermal resistance R for the conduction of energy.
The rate at which heat will flow through the wall or ceiling by conduction is dependent upon at least two factors: (1) the temperature difference and (2) the thermal resistance, R-value, of the total structure between the ambient and room temperature. To increase the efficiency of heating or cooling a structure to retard the flow of heat, more insulation or more efficient insulation is used. This has resulted in thicker walls to accommodate more insulation. Ceilings beneath the attic space are inherently unrestricted for additional passive insulation. Once the insulation is installed the heat transfer characteristics remain fixed regardless of the fluctuating ambient temperatures.
Several techniques to change the temperature difference between the ambient and room temperature have used air currents within the wall cavity. The air currents on occasion have been tempered by earth thermal energy or solar energy. Pluralities of air channels that carry the energy have been employed from both bottom to top and top to bottom of the wall cavity. Complete coverage of the building envelope in air channels has been proposed in U.S. Pat. No. 5,761,864 which describes a building comprising an exterior wall having a plurality of vertical air channels. The U.S. Pat. No. 5,761,864 patent does not disclose the treatment of an external wall with structural openings. There is no airflow or conductive ply to transfer the energy perpendicular to areas over and under the structural openings. Phase change material within the wall cavity accomplishes a constant temperature difference between the room temperature and the phase change material. The phase change material and containment are cumbersome because the material changes from solid to liquid and back again. A source of energy is required to accomplish the reversal.
There is therefore, a need in the art for a more efficient method of insulating a building structure.